Physiological Characteristics of Field Bean Seeds (Vicia faba var. minor) Subjected to 30 Years of Storage

Abstract

Seed vigour and viability, synchronous fluorescence spectroscopy, and proteomic profiles were analysed in field bean (Vicia faba var. minor) (Vicia faba var. minor) seeds (two cultivars) subjected to dry storage at −14 °C or +20 °C for 30 years. The seeds stored at −14 °C retained very high germinability (91–98%) until the end of the experiments, while seeds from the same lots but stored at room temperature completely lost viability. The deterioration of seeds stored at +20 °C was also manifested by a vast (4- to 6-fold) increase in leachate electroconductivity, and the changes in synchronous spectra and proteomic profiles. To carry out detailed analyses of seed proteins, protein extracts were pre-purified and divided into albumin, vicilin, and legumin. Only one protein, superoxide dismutase, was more abundant in deteriorated seeds (of one cultivar) compared to the high vigour seeds. The results show that seed deterioration strongly and specifically affects the contents of some storage proteins. Moreover, the colour of seed coats changes gradually, and seeds stored at −14 °C were light brown, while those constantly exposed to +20 °C turned black. Synchronous fluorescence spectroscopy showed that this change of colour was caused by formation of oxidized and condensed phenols and that the phenol content in seed coats decreased parallel to seed deterioration.